The present invention relates to an ignition sparking plug, wherein the end of the grounding electrode in the ignition sparking plug near the central electrode is manufactured as a tip end so as to reduce the area in the central electrode to be shielded by the grounding electrode. Therefore, as the ignition sparking plug is used, the mixed gas within the cylinder can be burned rapidly, meanwhile, the material used is saved.
With reference to FIG. 1, the ignition sparking plug 10 is assembled in the cylinder 11. By discharging between the central electrode 12 at one end thereof and the grounding electrode 13, an electric spark is generated so as to combust the mixing gas (formed by oil and air) in the cylinder 11 to cause an explosion. Therefore, the piston 110 is pushed away.
In practical operation, in two strokes of the engine, all the cylinders 11 must be operated one time. For an operation of 3000 revolutions per minutes (rpm), the engine revolves through 50 circles per second. In other words, each cylinder moves 25 times in each second. Thus, it should be understand that the actuation time of the ignition sparking plug is very short. In order that the explosion of the ignition sparking plug is more practical and is pushed smoothly, the mixing gas must enter into the space between the central electrode 12 and the grounding electrode 13 in a very short time (before explosion, the space within the cylinder is in a vacuum state, thus mixed gas necessarily enters into the space, and is ignited in the space between the central electrode and the grounding electrode). However, in general, the grounding electrode 13 of an ignition sparking plug 10 is a flat plate which shield the central electrode 12 completely. Thus, the mixed gas is very difficult to enter into the space between the central electrode 12 and the grounding electrode 13 in a very short time. As a result, the function of the ignition sparking plug 10 and the action of the cylinder 11 are affected. Therefore, many improvements are performed for improving such kind of prior art ignition sparking plug.
With reference to FIGS. 2 and 3, wherein a cruciform trench 14 or a V shape trench 15 is formed in the central electrode 12 so as to increase the space connected the central electrode 12 and the grounding electrode 13. Thus, by this enlarged space, the mixed gas can flow this space rapidly. Referring to FIG. 4, a trench 16 is formed at the inner surface of the grounding electrode 13 with respect to the central electrode 12 so as to increase the space between the central electrode 12 and the grounding electrode 13. Thus, mixed gas may enter into this space. Besides, referring to FIG. 5, the grounding electrode 13 is made with a shorter length for reducing the shielding of the central electrode 12 so that mixed gas enters into the space between the central electrode 12 and the grounding electrode 13 rapidly for explosion. With reference to FIG. 6, a hole 17 is drilled in the grounding electrode 17 with respect the central electrode 12 so that mixed gas can enter into the space between the central electrode 12 and the grounding electrode 13 rapidly for next explosion.
The above improvements is aimed at the mixed gas may enter into a predetermined space. However, in above designs, the grounding electrode 13 still shields the central electrode 12 with a large area. Moreover, due to the width of the grounding electrode 13, the mixed gas 13 must move around the two sides of the grounding electrode 13 for entering into the space between central electrode 12 and the grounding electrode 13. Similarly, the firing mixed gas must flow around the two sides of the grounding electrode 13 for extending the combustion outwards. Therefore, the traveling of the mixed gas is not straight. In a short ignition, the explosion of the mixed gas will not be smooth, therefore, although the aforesaid improvements have the effect of improving the function of the prior art ignition sparking plug 10, the effect is not preferred.
Besides, when the ignition sparking plug 10 is ignited to spark, since the area of the grounding electrode 13 is too large, it will absorb a larger thermal energy and the expansion of the spark is prevented. As a result, the range of the spark is hindered. Furthermore, when cool mixed gas enters into the space, the surface of the ignition sparking plug 10 will be cooled so that the surfaces of the central electrode 12 and grounding electrode 13 have no function of ignition. Therefore, a grounding electrode designed with a larger area can not improve the performance of the ignition. As oil only occupies a small part of the mixed gas, it is possible that no explosion occurs. Accordingly, the air gate must be closed for increasing the concentration of the oil. This not only wastes oil, but also an incomplete combustion occurs and coal will accumulate. Therefore, aforesaid ignition sparking plug is not met the practical requirement and is necessary to be improved further.
Accordingly, the primary object of the present invention is to provide an improved structure of an ignition sparking plug having a grounding electrode and a central electrode. The grounding electrode has a tip end with respect to the central electrode so that the only a small part of the central electrode is shielded by the grounding electrode. Thereby, mixed gas enters into the space between the grounding electrode and the central electrode rapidly so as to be ignited and then explode quickly to push the piston. Therefore, the piston can move reciprocally. Since the grounding electrode has a smaller volume, the generated spark has a large volume and absorbs a little thermal energy. Since electric discharging occurs in a tip point, the efficiency of ignition is high so as to improve the air to oil ratio in the cylinder and thus oil is saved and exhausted waste is reduced.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.